1 /*
2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotClassInitializer.hpp"
27 #include "cds/aotClassLocation.hpp"
28 #include "cds/archiveBuilder.hpp"
29 #include "cds/archiveHeapLoader.hpp"
30 #include "cds/archiveHeapWriter.hpp"
31 #include "cds/archiveUtils.hpp"
32 #include "cds/cdsAccess.hpp"
33 #include "cds/cdsConfig.hpp"
34 #include "cds/cdsEnumKlass.hpp"
35 #include "cds/cdsHeapVerifier.hpp"
36 #include "cds/heapShared.hpp"
37 #include "cds/metaspaceShared.hpp"
38 #include "classfile/classLoaderData.hpp"
39 #include "classfile/classLoaderExt.hpp"
40 #include "classfile/javaClasses.inline.hpp"
41 #include "classfile/modules.hpp"
42 #include "classfile/stringTable.hpp"
43 #include "classfile/symbolTable.hpp"
44 #include "classfile/systemDictionary.hpp"
45 #include "classfile/systemDictionaryShared.hpp"
46 #include "classfile/vmClasses.hpp"
47 #include "classfile/vmSymbols.hpp"
48 #include "gc/shared/collectedHeap.hpp"
49 #include "gc/shared/gcLocker.hpp"
50 #include "gc/shared/gcVMOperations.hpp"
51 #include "logging/log.hpp"
52 #include "logging/logStream.hpp"
53 #include "memory/iterator.inline.hpp"
54 #include "memory/resourceArea.hpp"
55 #include "memory/universe.hpp"
56 #include "oops/compressedOops.inline.hpp"
57 #include "oops/fieldStreams.inline.hpp"
58 #include "oops/objArrayOop.inline.hpp"
59 #include "oops/oop.inline.hpp"
60 #include "oops/typeArrayOop.inline.hpp"
61 #include "prims/jvmtiExport.hpp"
62 #include "runtime/arguments.hpp"
63 #include "runtime/fieldDescriptor.inline.hpp"
64 #include "runtime/init.hpp"
65 #include "runtime/javaCalls.hpp"
66 #include "runtime/mutexLocker.hpp"
67 #include "runtime/safepointVerifiers.hpp"
68 #include "utilities/bitMap.inline.hpp"
69 #include "utilities/copy.hpp"
70 #if INCLUDE_G1GC
71 #include "gc/g1/g1CollectedHeap.hpp"
72 #endif
73
74 #if INCLUDE_CDS_JAVA_HEAP
75
76 struct ArchivableStaticFieldInfo {
77 const char* klass_name;
78 const char* field_name;
79 InstanceKlass* klass;
80 int offset;
81 BasicType type;
82
83 ArchivableStaticFieldInfo(const char* k, const char* f)
84 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
85
86 bool valid() {
87 return klass_name != nullptr;
88 }
89 };
90
91 class HeapShared::ContextMark : public StackObj {
92 ResourceMark rm;
93 public:
94 ContextMark(const char* c) : rm{} {
95 _context->push(c);
96 }
97 ~ContextMark() {
98 _context->pop();
99 }
100 };
101
102 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
103
104 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
105 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
106 size_t HeapShared::_total_obj_count;
107 size_t HeapShared::_total_obj_size;
108
109 #ifndef PRODUCT
110 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
111 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
112 static const char* _test_class_name = nullptr;
113 static Klass* _test_class = nullptr;
114 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
115 #endif
116
117
118 //
119 // If you add new entries to the following tables, you should know what you're doing!
120 //
121
122 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
123 {"java/lang/Integer$IntegerCache", "archivedCache"},
124 {"java/lang/Long$LongCache", "archivedCache"},
125 {"java/lang/Byte$ByteCache", "archivedCache"},
126 {"java/lang/Short$ShortCache", "archivedCache"},
127 {"java/lang/Character$CharacterCache", "archivedCache"},
128 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
129 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
130 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
131 {"java/util/ImmutableCollections", "archivedObjects"},
132 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
133 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
134 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
135 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
136
137 #ifndef PRODUCT
138 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
139 #endif
140 {nullptr, nullptr},
141 };
142
143 // full module graph
144 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
145 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
146 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
147 {"java/lang/Module$ArchivedData", "archivedData"},
148 {nullptr, nullptr},
149 };
150
151 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
152 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
153 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_pending_roots = nullptr;
154 GrowableArrayCHeap<const char*, mtClassShared>* HeapShared::_context = nullptr;
155 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments;
156 int HeapShared::_root_segment_max_size_elems;
157 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
158 MetaspaceObjToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr;
159 MetaspaceObjToOopHandleTable* HeapShared::_scratch_references_table = nullptr;
160
161 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
162 for (int i = 0; fields[i].valid(); i++) {
163 if (fields[i].klass == ik) {
164 return true;
165 }
166 }
167 return false;
168 }
169
170 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
171 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
172 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
173 }
174
175 unsigned HeapShared::oop_hash(oop const& p) {
176 // Do not call p->identity_hash() as that will update the
177 // object header.
178 return primitive_hash(cast_from_oop<intptr_t>(p));
179 }
180
181 static void reset_states(oop obj, TRAPS) {
182 Handle h_obj(THREAD, obj);
183 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
184 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
185 Symbol* method_sig = vmSymbols::void_method_signature();
186
187 while (klass != nullptr) {
188 Method* method = klass->find_method(method_name, method_sig);
189 if (method != nullptr) {
190 assert(method->is_private(), "must be");
191 if (log_is_enabled(Debug, cds)) {
192 ResourceMark rm(THREAD);
193 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
194 }
195 JavaValue result(T_VOID);
196 JavaCalls::call_special(&result, h_obj, klass,
197 method_name, method_sig, CHECK);
198 }
199 klass = klass->java_super();
200 }
201 }
202
203 void HeapShared::reset_archived_object_states(TRAPS) {
204 assert(CDSConfig::is_dumping_heap(), "dump-time only");
205 log_debug(cds)("Resetting platform loader");
206 reset_states(SystemDictionary::java_platform_loader(), CHECK);
207 log_debug(cds)("Resetting system loader");
208 reset_states(SystemDictionary::java_system_loader(), CHECK);
209
210 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
211 // directly used for class loading, but rather is used by the core library
212 // to keep track of resources, etc, loaded by the null class loader.
213 //
214 // Note, this object is non-null, and is not the same as
215 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
216 // which is null.
217 log_debug(cds)("Resetting boot loader");
218 JavaValue result(T_OBJECT);
219 JavaCalls::call_static(&result,
220 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
221 vmSymbols::bootLoader_name(),
222 vmSymbols::void_BuiltinClassLoader_signature(),
223 CHECK);
224 Handle boot_loader(THREAD, result.get_oop());
225 reset_states(boot_loader(), CHECK);
226 }
227
228 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
229
230 bool HeapShared::has_been_archived(oop obj) {
231 assert(CDSConfig::is_dumping_heap(), "dump-time only");
232 return archived_object_cache()->get(obj) != nullptr;
233 }
234
235 int HeapShared::append_root(oop obj) {
236 assert(CDSConfig::is_dumping_heap(), "dump-time only");
237 if (obj != nullptr) {
238 assert(has_been_archived(obj), "must be");
239 }
240 // No GC should happen since we aren't scanning _pending_roots.
241 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
242
243 if (_pending_roots == nullptr) {
244 _pending_roots = new GrowableArrayCHeap<OopHandle, mtClassShared>(500);
245 }
246
247 OopHandle oh(Universe::vm_global(), obj);
248 return _pending_roots->append(oh);
249 }
250
251 objArrayOop HeapShared::root_segment(int segment_idx) {
252 if (CDSConfig::is_dumping_heap() && !CDSConfig::is_dumping_final_static_archive()) {
253 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
254 } else {
255 assert(CDSConfig::is_using_archive(), "must be");
256 }
257
258 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
259 assert(segment != nullptr, "should have been initialized");
260 return segment;
261 }
262
263 inline unsigned int oop_handle_hash(const OopHandle& oh) {
264 oop o = oh.resolve();
265 if (o == nullptr) {
266 return 0;
267 } else {
268 return o->identity_hash();
269 }
270 }
271
272 inline bool oop_handle_equals(const OopHandle& a, const OopHandle& b) {
273 return a.resolve() == b.resolve();
274 }
275
276 class OrigToScratchObjectTable: public ResourceHashtable<OopHandle, OopHandle,
277 36137, // prime number
278 AnyObj::C_HEAP,
279 mtClassShared,
280 oop_handle_hash,
281 oop_handle_equals> {};
282
283 static OrigToScratchObjectTable* _orig_to_scratch_object_table = nullptr;
284
285 void HeapShared::track_scratch_object(oop orig_obj, oop scratch_obj) {
286 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
287 if (_orig_to_scratch_object_table == nullptr) {
288 _orig_to_scratch_object_table = new (mtClass)OrigToScratchObjectTable();
289 }
290
291 OopHandle orig_h(Universe::vm_global(), orig_obj);
292 OopHandle scratch_h(Universe::vm_global(), scratch_obj);
293 _orig_to_scratch_object_table->put_when_absent(orig_h, scratch_h);
294 }
295
296 oop HeapShared::orig_to_scratch_object(oop orig_obj) {
297 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
298 if (_orig_to_scratch_object_table != nullptr) {
299 OopHandle orig(&orig_obj);
300 OopHandle* v = _orig_to_scratch_object_table->get(orig);
301 if (v != nullptr) {
302 return v->resolve();
303 }
304 }
305 return nullptr;
306 }
307
308 // Permanent oops are used to support AOT-compiled methods, which may have in-line references
309 // to Strings and MH oops.
310 //
311 // At runtime, these oops are stored in _runtime_permanent_oops (which keeps them alive forever)
312 // and are accssed vis CDSAccess::get_archived_object(int).
313 struct PermanentOopInfo {
314 int _index; // Gets assigned only if HeapShared::get_archived_object_permanent_index() has been called on the object
315 int _heap_offset; // Offset of the object from the bottom of the archived heap.
316 PermanentOopInfo(int index, int heap_offset) : _index(index), _heap_offset(heap_offset) {}
317 };
318
319 class PermanentOopTable: public ResourceHashtable<OopHandle, PermanentOopInfo,
320 36137, // prime number
321 AnyObj::C_HEAP,
322 mtClassShared,
323 oop_handle_hash,
324 oop_handle_equals> {};
325
326 static int _dumptime_permanent_oop_count = 0;
327 static PermanentOopTable* _dumptime_permanent_oop_table = nullptr;
328 static GrowableArrayCHeap<OopHandle, mtClassShared>* _runtime_permanent_oops = nullptr;
329
330 // ArchiveHeapWriter adds each archived heap object to _dumptime_permanent_oop_table,
331 // so we can remember their offset (from the bottom of the archived heap).
332 void HeapShared::add_to_permanent_oop_table(oop obj, int offset) {
333 assert_at_safepoint();
334 if (_dumptime_permanent_oop_table == nullptr) {
335 _dumptime_permanent_oop_table = new (mtClass)PermanentOopTable();
336 }
337
338 PermanentOopInfo info(-1, offset);
339 OopHandle oh(Universe::vm_global(), obj);
340 _dumptime_permanent_oop_table->put_when_absent(oh, info);
341 }
342
343 // A permanent index is assigned to an archived object ONLY when
344 // the AOT compiler calls this function.
345 int HeapShared::get_archived_object_permanent_index(oop obj) {
346 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
347
348 if (!CDSConfig::is_dumping_heap()) {
349 return -1; // Called by the Leyden old workflow
350 }
351 if (_dumptime_permanent_oop_table == nullptr) {
352 return -1;
353 }
354
355 if (_orig_to_scratch_object_table != nullptr) {
356 OopHandle orig(&obj);
357 OopHandle* v = _orig_to_scratch_object_table->get(orig);
358 if (v != nullptr) {
359 obj = v->resolve();
360 }
361 }
362
363 OopHandle tmp(&obj);
364 PermanentOopInfo* info = _dumptime_permanent_oop_table->get(tmp);
365 if (info == nullptr) {
366 return -1;
367 } else {
368 if (info->_index < 0) {
369 info->_index = _dumptime_permanent_oop_count++;
370 }
371 return info->_index;
372 }
373 }
374
375 oop HeapShared::get_archived_object(int permanent_index) {
376 assert(permanent_index >= 0, "sanity");
377 assert(ArchiveHeapLoader::is_in_use(), "sanity");
378 assert(_runtime_permanent_oops != nullptr, "sanity");
379
380 return _runtime_permanent_oops->at(permanent_index).resolve();
381 }
382
383 // Remember all archived heap objects that have a permanent index.
384 // table[i] = offset of oop whose permanent index is i.
385 void CachedCodeDirectoryInternal::dumptime_init_internal() {
386 const int count = _dumptime_permanent_oop_count;
387 if (count == 0) {
388 // Avoid confusing CDS code with zero-sized tables, just return.
389 log_info(cds)("No permanent oops");
390 _permanent_oop_count = count;
391 _permanent_oop_offsets = nullptr;
392 return;
393 }
394
395 int* table = (int*)CDSAccess::allocate_from_code_cache(count * sizeof(int));
396 for (int i = 0; i < count; i++) {
397 table[count] = -1;
398 }
399 _dumptime_permanent_oop_table->iterate([&](OopHandle o, PermanentOopInfo& info) {
400 int index = info._index;
401 if (index >= 0) {
402 assert(index < count, "sanity");
403 table[index] = info._heap_offset;
404 }
405 return true; // continue
406 });
407
408 for (int i = 0; i < count; i++) {
409 assert(table[i] >= 0, "must be");
410 }
411
412 log_info(cds)("Dumped %d permanent oops", count);
413
414 _permanent_oop_count = count;
415 CDSAccess::set_pointer(&_permanent_oop_offsets, table);
416 }
417
418 // This is called during the bootstrap of the production run, before any GC can happen.
419 // Record each permanent oop in a OopHandle for GC safety.
420 void CachedCodeDirectoryInternal::runtime_init_internal() {
421 int count = _permanent_oop_count;
422 int* table = _permanent_oop_offsets;
423 _runtime_permanent_oops = new GrowableArrayCHeap<OopHandle, mtClassShared>();
424 for (int i = 0; i < count; i++) {
425 oop obj = ArchiveHeapLoader::oop_from_offset(table[i]);
426 OopHandle oh(Universe::vm_global(), obj);
427 _runtime_permanent_oops->append(oh);
428 }
429 };
430
431 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) {
432 assert(_root_segment_max_size_elems > 0, "sanity");
433
434 // Try to avoid divisions for the common case.
435 if (idx < _root_segment_max_size_elems) {
436 seg_idx = 0;
437 int_idx = idx;
438 } else {
439 seg_idx = idx / _root_segment_max_size_elems;
440 int_idx = idx % _root_segment_max_size_elems;
441 }
442
443 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx,
444 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx);
445 }
446
447 // Returns an objArray that contains all the roots of the archived objects
448 oop HeapShared::get_root(int index, bool clear) {
449 assert(index >= 0, "sanity");
450 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
451 assert(!_root_segments->is_empty(), "must have loaded shared heap");
452 int seg_idx, int_idx;
453 get_segment_indexes(index, seg_idx, int_idx);
454 oop result = root_segment(seg_idx)->obj_at(int_idx);
455 if (clear) {
456 clear_root(index);
457 }
458 return result;
459 }
460
461 void HeapShared::clear_root(int index) {
462 assert(index >= 0, "sanity");
463 assert(CDSConfig::is_using_archive(), "must be");
464 if (ArchiveHeapLoader::is_in_use()) {
465 int seg_idx, int_idx;
466 get_segment_indexes(index, seg_idx, int_idx);
467 if (log_is_enabled(Debug, cds, heap)) {
468 oop old = root_segment(seg_idx)->obj_at(int_idx);
469 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
470 }
471 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
472 }
473 }
474
475 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
476 assert(CDSConfig::is_dumping_heap(), "dump-time only");
477
478 assert(!obj->is_stackChunk(), "do not archive stack chunks");
479 if (has_been_archived(obj)) {
480 return true;
481 }
482
483 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
484 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
485 p2i(obj), obj->size());
486 debug_trace();
487 return false;
488 } else {
489 count_allocation(obj->size());
490 ArchiveHeapWriter::add_source_obj(obj);
491 CachedOopInfo info = make_cached_oop_info(obj, referrer);
492 archived_object_cache()->put_when_absent(obj, info);
493 archived_object_cache()->maybe_grow();
494 mark_native_pointers(obj);
495
496 Klass* k = obj->klass();
497 if (k->is_instance_klass()) {
498 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
499 // This ensures that during the production run, whenever Java code sees a cached object
500 // of type X, we know that X is already initialized. (see TODO comment below ...)
501
502 if (InstanceKlass::cast(k)->is_enum_subclass()
503 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
504 // we must store them as AOT-initialized.
505 || (subgraph_info == _dump_time_special_subgraph))
506 // TODO: we do this only for the special subgraph for now. Extending this to
507 // other subgraphs would require more refactoring of the core library (such as
508 // move some initialization logic into runtimeSetup()).
509 //
510 // For the other subgraphs, we have a weaker mechanism to ensure that
511 // all classes in a subgraph are initialized before the subgraph is programmatically
512 // returned from jdk.internal.misc.CDS::initializeFromArchive().
513 // See HeapShared::initialize_from_archived_subgraph().
514 {
515 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
516 }
517
518 if (java_lang_Class::is_instance(obj)) {
519 Klass* mirror_k = java_lang_Class::as_Klass(obj);
520 if (mirror_k != nullptr) {
521 AOTArtifactFinder::add_cached_class(mirror_k);
522 }
523 }
524 }
525
526 if (log_is_enabled(Debug, cds, heap)) {
527 ResourceMark rm;
528 LogTarget(Debug, cds, heap) log;
529 LogStream out(log);
530 out.print("Archived heap object " PTR_FORMAT " : %s ",
531 p2i(obj), obj->klass()->external_name());
532 if (java_lang_Class::is_instance(obj)) {
533 Klass* k = java_lang_Class::as_Klass(obj);
534 if (k != nullptr) {
535 out.print("%s", k->external_name());
536 } else {
537 out.print("primitive");
538 }
539 }
540 out.cr();
541 }
542
543 return true;
544 }
545 }
546
547 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle,
548 36137, // prime number
549 AnyObj::C_HEAP,
550 mtClassShared> {
551 public:
552 oop get_oop(MetaspaceObj* ptr) {
553 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
554 OopHandle* handle = get(ptr);
555 if (handle != nullptr) {
556 return handle->resolve();
557 } else {
558 return nullptr;
559 }
560 }
561 void set_oop(MetaspaceObj* ptr, oop o) {
562 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
563 OopHandle handle(Universe::vm_global(), o);
564 bool is_new = put(ptr, handle);
565 assert(is_new, "cannot set twice");
566 }
567 void remove_oop(MetaspaceObj* ptr) {
568 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
569 OopHandle* handle = get(ptr);
570 if (handle != nullptr) {
571 handle->release(Universe::vm_global());
572 remove(ptr);
573 }
574 }
575 };
576
577 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
578 if (_scratch_references_table == nullptr) {
579 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
580 }
581 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
582 _scratch_references_table->set_oop(src, dest);
583 }
584 }
585
586 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
587 return (objArrayOop)_scratch_references_table->get_oop(src);
588 }
589
590 void HeapShared::init_dumping() {
591 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable();
592 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
593 }
594
595 void HeapShared::init_scratch_objects(TRAPS) {
596 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
597 BasicType bt = (BasicType)i;
598 if (!is_reference_type(bt)) {
599 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
600 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
601 track_scratch_object(Universe::java_mirror(bt), m);
602 }
603 }
604 }
605
606 // Given java_mirror that represents a (primitive or reference) type T,
607 // return the "scratch" version that represents the same type T.
608 // Note that if java_mirror will be returned if it's already a
609 // scratch mirror.
610 //
611 // See java_lang_Class::create_scratch_mirror() for more info.
612 oop HeapShared::scratch_java_mirror(oop java_mirror) {
613 assert(java_lang_Class::is_instance(java_mirror), "must be");
614
615 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
616 BasicType bt = (BasicType)i;
617 if (!is_reference_type(bt)) {
618 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
619 return java_mirror;
620 }
621 }
622 }
623
624 if (java_lang_Class::is_primitive(java_mirror)) {
625 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
626 } else {
627 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
628 }
629 }
630
631 oop HeapShared::scratch_java_mirror(BasicType t) {
632 assert((uint)t < T_VOID+1, "range check");
633 assert(!is_reference_type(t), "sanity");
634 return _scratch_basic_type_mirrors[t].resolve();
635 }
636
637 oop HeapShared::scratch_java_mirror(Klass* k) {
638 return _scratch_java_mirror_table->get_oop(k);
639 }
640
641 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
642 track_scratch_object(k->java_mirror(), mirror);
643 _scratch_java_mirror_table->set_oop(k, mirror);
644 }
645
646 void HeapShared::remove_scratch_objects(Klass* k) {
647 // Klass is being deallocated. Java mirror can still be alive, and it should not
648 // point to dead klass. We need to break the link from mirror to the Klass.
649 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
650 oop mirror = _scratch_java_mirror_table->get_oop(k);
651 if (mirror != nullptr) {
652 java_lang_Class::set_klass(mirror, nullptr);
653 }
654 _scratch_java_mirror_table->remove_oop(k);
655 if (k->is_instance_klass()) {
656 _scratch_references_table->remove(InstanceKlass::cast(k)->constants());
657 }
658 if (mirror != nullptr) {
659 OopHandle tmp(&mirror);
660 OopHandle* v = _orig_to_scratch_object_table->get(tmp);
661 if (v != nullptr) {
662 oop scratch_mirror = v->resolve();
663 java_lang_Class::set_klass(scratch_mirror, nullptr);
664 _orig_to_scratch_object_table->remove(tmp);
665 }
666 }
667 }
668
669 //TODO: we eventually want a more direct test for these kinds of things.
670 //For example the JVM could record some bit of context from the creation
671 //of the klass, such as who called the hidden class factory. Using
672 //string compares on names is fragile and will break as soon as somebody
673 //changes the names in the JDK code. See discussion in JDK-8342481 for
674 //related ideas about marking AOT-related classes.
675 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
676 return ik->is_hidden() &&
677 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
678 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
679 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
680 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
681 }
682
683 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
684 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
685 }
686
687 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
688 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
689 }
690
691 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
692 return CDSConfig::is_dumping_invokedynamic() &&
693 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
694 }
695
696
697 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
698 ik->set_has_aot_initialized_mirror();
699 if (AOTClassInitializer::is_runtime_setup_required(ik)) {
700 ik->set_is_runtime_setup_required();
701 }
702
703 oop orig_mirror = ik->java_mirror();
704 oop m = scratch_java_mirror(ik);
705 assert(ik->is_initialized(), "must be");
706
707 int nfields = 0;
708 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
709 if (fs.access_flags().is_static()) {
710 fieldDescriptor& fd = fs.field_descriptor();
711 int offset = fd.offset();
712 switch (fd.field_type()) {
713 case T_OBJECT:
714 case T_ARRAY:
715 {
716 oop field_obj = orig_mirror->obj_field(offset);
717 if (offset == java_lang_Class::reflection_data_offset()) {
718 // Class::reflectData use SoftReference, which cannot be archived. Set it
719 // to null and it will be recreated at runtime.
720 field_obj = nullptr;
721 }
722 m->obj_field_put(offset, field_obj);
723 if (field_obj != nullptr) {
724 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
725 assert(success, "sanity");
726 }
727 }
728 break;
729 case T_BOOLEAN:
730 m->bool_field_put(offset, orig_mirror->bool_field(offset));
731 break;
732 case T_BYTE:
733 m->byte_field_put(offset, orig_mirror->byte_field(offset));
734 break;
735 case T_SHORT:
736 m->short_field_put(offset, orig_mirror->short_field(offset));
737 break;
738 case T_CHAR:
739 m->char_field_put(offset, orig_mirror->char_field(offset));
740 break;
741 case T_INT:
742 m->int_field_put(offset, orig_mirror->int_field(offset));
743 break;
744 case T_LONG:
745 m->long_field_put(offset, orig_mirror->long_field(offset));
746 break;
747 case T_FLOAT:
748 m->float_field_put(offset, orig_mirror->float_field(offset));
749 break;
750 case T_DOUBLE:
751 m->double_field_put(offset, orig_mirror->double_field(offset));
752 break;
753 default:
754 ShouldNotReachHere();
755 }
756 nfields ++;
757 }
758 }
759
760 oop class_data = java_lang_Class::class_data(orig_mirror);
761 java_lang_Class::set_class_data(m, class_data);
762 if (class_data != nullptr) {
763 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
764 assert(success, "sanity");
765 }
766
767 if (log_is_enabled(Info, cds, init)) {
768 ResourceMark rm;
769 log_debug(cds, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
770 ik->is_hidden() ? " (hidden)" : "",
771 ik->is_enum_subclass() ? " (enum)" : "");
772 }
773 }
774
775 static void copy_java_mirror_hashcode(oop orig_mirror, oop scratch_m) {
776 // We need to retain the identity_hash, because it may have been used by some hashtables
777 // in the shared heap.
778 if (!orig_mirror->fast_no_hash_check()) {
779 intptr_t src_hash = orig_mirror->identity_hash();
780 if (UseCompactObjectHeaders) {
781 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
782 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
783 } else {
784 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
785 }
786 assert(scratch_m->mark().is_unlocked(), "sanity");
787
788 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
789 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
790 }
791 }
792
793 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
794 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
795 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
796 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
797 return HeapShared::scratch_resolved_references(src_ik->constants());
798 }
799 }
800 return nullptr;
801 }
802
803 void HeapShared::archive_strings() {
804 oop shared_strings_array = StringTable::init_shared_strings_array(_dumped_interned_strings);
805 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
806 // We must succeed because:
807 // - _dumped_interned_strings do not contain any large strings.
808 // - StringTable::init_shared_table() doesn't create any large arrays.
809 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
810 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
811 }
812
813 int HeapShared::archive_exception_instance(oop exception) {
814 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
815 assert(success, "sanity");
816 return append_root(exception);
817 }
818
819 void HeapShared::mark_native_pointers(oop orig_obj) {
820 if (java_lang_Class::is_instance(orig_obj)) {
821 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
822 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
823 } else if (java_lang_invoke_ResolvedMethodName::is_instance(orig_obj)) {
824 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_invoke_ResolvedMethodName::vmtarget_offset());
825 }
826 }
827
828 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
829 CachedOopInfo* info = archived_object_cache()->get(src_obj);
830 assert(info != nullptr, "must be");
831 has_oop_pointers = info->has_oop_pointers();
832 has_native_pointers = info->has_native_pointers();
833 }
834
835 void HeapShared::set_has_native_pointers(oop src_obj) {
836 CachedOopInfo* info = archived_object_cache()->get(src_obj);
837 assert(info != nullptr, "must be");
838 info->set_has_native_pointers();
839 }
840
841 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
842 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
843 void HeapShared::start_scanning_for_oops() {
844 {
845 NoSafepointVerifier nsv;
846
847 // The special subgraph doesn't belong to any class. We use Object_klass() here just
848 // for convenience.
849 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
850 _context = new GrowableArrayCHeap<const char*, mtClassShared>(250);
851
852 // Cache for recording where the archived objects are copied to
853 create_archived_object_cache();
854
855 if (UseCompressedOops || UseG1GC) {
856 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
857 UseCompressedOops ? p2i(CompressedOops::begin()) :
858 p2i((address)G1CollectedHeap::heap()->reserved().start()),
859 UseCompressedOops ? p2i(CompressedOops::end()) :
860 p2i((address)G1CollectedHeap::heap()->reserved().end()));
861 }
862
863 archive_subgraphs();
864 }
865
866 init_seen_objects_table();
867 Universe::archive_exception_instances();
868 }
869
870 void HeapShared::end_scanning_for_oops() {
871 archive_strings();
872 delete_seen_objects_table();
873 }
874
875 void HeapShared::write_heap(ArchiveHeapInfo *heap_info) {
876 {
877 NoSafepointVerifier nsv;
878 if (!SkipArchiveHeapVerification) {
879 CDSHeapVerifier::verify();
880 }
881 check_special_subgraph_classes();
882 }
883
884 StringTable::write_shared_table(_dumped_interned_strings);
885 GrowableArrayCHeap<oop, mtClassShared>* roots = new GrowableArrayCHeap<oop, mtClassShared>(_pending_roots->length());
886 for (int i = 0; i < _pending_roots->length(); i++) {
887 roots->append(_pending_roots->at(i).resolve());
888 }
889 ArchiveHeapWriter::write(roots, heap_info);
890 delete roots;
891
892 ArchiveBuilder::OtherROAllocMark mark;
893 write_subgraph_info_table();
894 }
895
896 void HeapShared::scan_java_mirror(oop orig_mirror) {
897 oop m = scratch_java_mirror(orig_mirror);
898 if (m != nullptr) { // nullptr if for custom class loader
899 copy_java_mirror_hashcode(orig_mirror, m);
900 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
901 assert(success, "sanity");
902 }
903 }
904
905 void HeapShared::scan_java_class(Klass* orig_k) {
906 scan_java_mirror(orig_k->java_mirror());
907
908 if (orig_k->is_instance_klass()) {
909 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
910 orig_ik->constants()->prepare_resolved_references_for_archiving();
911 objArrayOop rr = get_archived_resolved_references(orig_ik);
912 if (rr != nullptr) {
913 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
914 assert(success, "must be");
915 }
916
917 orig_ik->constants()->add_dumped_interned_strings();
918 }
919 }
920
921 void HeapShared::archive_subgraphs() {
922 assert(CDSConfig::is_dumping_heap(), "must be");
923
924 archive_object_subgraphs(archive_subgraph_entry_fields,
925 false /* is_full_module_graph */);
926
927 if (CDSConfig::is_dumping_full_module_graph()) {
928 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
929 true /* is_full_module_graph */);
930 Modules::verify_archived_modules();
931 }
932 }
933
934 //
935 // Subgraph archiving support
936 //
937 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
938 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
939
940 // Get the subgraph_info for Klass k. A new subgraph_info is created if
941 // there is no existing one for k. The subgraph_info records the "buffered"
942 // address of the class.
943 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
944 assert(CDSConfig::is_dumping_heap(), "dump time only");
945 bool created;
946 KlassSubGraphInfo* info =
947 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
948 &created);
949 assert(created, "must not initialize twice");
950 return info;
951 }
952
953 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
954 assert(CDSConfig::is_dumping_heap(), "dump time only");
955 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
956 assert(info != nullptr, "must have been initialized");
957 return info;
958 }
959
960 // Add an entry field to the current KlassSubGraphInfo.
961 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
962 assert(CDSConfig::is_dumping_heap(), "dump time only");
963 if (_subgraph_entry_fields == nullptr) {
964 _subgraph_entry_fields =
965 new (mtClass) GrowableArray<int>(10, mtClass);
966 }
967 _subgraph_entry_fields->append(static_field_offset);
968 _subgraph_entry_fields->append(HeapShared::append_root(v));
969 }
970
971 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
972 // Only objects of boot classes can be included in sub-graph.
973 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
974 assert(CDSConfig::is_dumping_heap(), "dump time only");
975
976 if (_subgraph_object_klasses == nullptr) {
977 _subgraph_object_klasses =
978 new (mtClass) GrowableArray<Klass*>(50, mtClass);
979 }
980
981 if (_k == orig_k) {
982 // Don't add the Klass containing the sub-graph to it's own klass
983 // initialization list.
984 return;
985 }
986
987 if (orig_k->is_instance_klass()) {
988 #ifdef ASSERT
989 InstanceKlass* ik = InstanceKlass::cast(orig_k);
990 if (CDSConfig::is_dumping_invokedynamic()) {
991 assert(ik->class_loader() == nullptr ||
992 HeapShared::is_lambda_proxy_klass(ik),
993 "we can archive only instances of boot classes or lambda proxy classes");
994 } else {
995 assert(ik->class_loader() == nullptr, "must be boot class");
996 }
997 #endif
998 // vmClasses::xxx_klass() are not updated, need to check
999 // the original Klass*
1000 if (orig_k == vmClasses::String_klass() ||
1001 orig_k == vmClasses::Object_klass()) {
1002 // Initialized early during VM initialization. No need to be added
1003 // to the sub-graph object class list.
1004 return;
1005 }
1006 check_allowed_klass(InstanceKlass::cast(orig_k));
1007 } else if (orig_k->is_objArray_klass()) {
1008 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1009 if (abk->is_instance_klass()) {
1010 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
1011 "must be boot class");
1012 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1013 }
1014 if (orig_k == Universe::objectArrayKlass()) {
1015 // Initialized early during Universe::genesis. No need to be added
1016 // to the list.
1017 return;
1018 }
1019 } else {
1020 assert(orig_k->is_typeArray_klass(), "must be");
1021 // Primitive type arrays are created early during Universe::genesis.
1022 return;
1023 }
1024
1025 if (log_is_enabled(Debug, cds, heap)) {
1026 if (!_subgraph_object_klasses->contains(orig_k)) {
1027 ResourceMark rm;
1028 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
1029 }
1030 }
1031
1032 _subgraph_object_klasses->append_if_missing(orig_k);
1033 _has_non_early_klasses |= is_non_early_klass(orig_k);
1034 }
1035
1036 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1037 if (CDSConfig::is_dumping_invokedynamic()) {
1038 // FIXME -- this allows LambdaProxy classes
1039 return;
1040 }
1041 if (ik->module()->name() == vmSymbols::java_base()) {
1042 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1043 return;
1044 }
1045
1046 const char* lambda_msg = "";
1047 if (CDSConfig::is_dumping_invokedynamic()) {
1048 lambda_msg = ", or a lambda proxy class";
1049 if (HeapShared::is_lambda_proxy_klass(ik) &&
1050 (ik->class_loader() == nullptr ||
1051 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1052 ik->class_loader() == SystemDictionary::java_system_loader())) {
1053 return;
1054 }
1055 }
1056
1057 #ifndef PRODUCT
1058 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1059 // This class is loaded by ArchiveHeapTestClass
1060 return;
1061 }
1062 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1063 #else
1064 const char* testcls_msg = "";
1065 #endif
1066
1067 ResourceMark rm;
1068 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1069 ik->external_name(), lambda_msg, testcls_msg);
1070 MetaspaceShared::unrecoverable_writing_error();
1071 }
1072
1073 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1074 if (k->is_objArray_klass()) {
1075 k = ObjArrayKlass::cast(k)->bottom_klass();
1076 }
1077 if (k->is_instance_klass()) {
1078 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1079 ResourceMark rm;
1080 log_info(cds, heap)("non-early: %s", k->external_name());
1081 return true;
1082 } else {
1083 return false;
1084 }
1085 } else {
1086 return false;
1087 }
1088 }
1089
1090 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1091 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1092 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1093 _entry_field_records = nullptr;
1094 _subgraph_object_klasses = nullptr;
1095 _is_full_module_graph = info->is_full_module_graph();
1096
1097 if (_is_full_module_graph) {
1098 // Consider all classes referenced by the full module graph as early -- we will be
1099 // allocating objects of these classes during JVMTI early phase, so they cannot
1100 // be processed by (non-early) JVMTI ClassFileLoadHook
1101 _has_non_early_klasses = false;
1102 } else {
1103 _has_non_early_klasses = info->has_non_early_klasses();
1104 }
1105
1106 if (_has_non_early_klasses) {
1107 ResourceMark rm;
1108 log_info(cds, heap)(
1109 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1110 _k->external_name());
1111 }
1112
1113 // populate the entry fields
1114 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1115 if (entry_fields != nullptr) {
1116 int num_entry_fields = entry_fields->length();
1117 assert(num_entry_fields % 2 == 0, "sanity");
1118 _entry_field_records =
1119 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1120 for (int i = 0 ; i < num_entry_fields; i++) {
1121 _entry_field_records->at_put(i, entry_fields->at(i));
1122 }
1123 }
1124
1125 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1126 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1127 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1128 if (recorded_klasses != nullptr) {
1129 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1130 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1131 // that are not aot-inited.
1132 int num_to_copy = 0;
1133 for (int i = 0; i < recorded_klasses->length(); i++) {
1134 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1135 if (!subgraph_k->has_aot_initialized_mirror()) {
1136 num_to_copy ++;
1137 }
1138 }
1139
1140 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1141 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1142 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1143 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1144 if (subgraph_k->has_aot_initialized_mirror()) {
1145 continue;
1146 }
1147 if (log_is_enabled(Info, cds, heap)) {
1148 ResourceMark rm;
1149 const char* owner_name = is_special ? "<special>" : _k->external_name();
1150 if (subgraph_k->is_instance_klass()) {
1151 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1152 }
1153 log_info(cds, heap)(
1154 "Archived object klass %s (%2d) => %s",
1155 owner_name, n, subgraph_k->external_name());
1156 }
1157 _subgraph_object_klasses->at_put(n, subgraph_k);
1158 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1159 n++;
1160 }
1161 }
1162
1163 ArchivePtrMarker::mark_pointer(&_k);
1164 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1165 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1166 }
1167
1168 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1169 CompactHashtableWriter* _writer;
1170 public:
1171 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1172
1173 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1174 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1175 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1176 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1177 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1178 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1179 _writer->add(hash, delta);
1180 }
1181 return true; // keep on iterating
1182 }
1183 };
1184
1185 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1186 ArchivedKlassSubGraphInfoRecord* record =
1187 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1188 record->init(info);
1189 if (info == _dump_time_special_subgraph) {
1190 _run_time_special_subgraph = record;
1191 }
1192 return record;
1193 }
1194
1195 // Build the records of archived subgraph infos, which include:
1196 // - Entry points to all subgraphs from the containing class mirror. The entry
1197 // points are static fields in the mirror. For each entry point, the field
1198 // offset, and value are recorded in the sub-graph
1199 // info. The value is stored back to the corresponding field at runtime.
1200 // - A list of klasses that need to be loaded/initialized before archived
1201 // java object sub-graph can be accessed at runtime.
1202 void HeapShared::write_subgraph_info_table() {
1203 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1204 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1205 CompactHashtableStats stats;
1206
1207 _run_time_subgraph_info_table.reset();
1208
1209 CompactHashtableWriter writer(d_table->_count, &stats);
1210 CopyKlassSubGraphInfoToArchive copy(&writer);
1211 d_table->iterate(©);
1212 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1213
1214 #ifndef PRODUCT
1215 if (ArchiveHeapTestClass != nullptr) {
1216 size_t len = strlen(ArchiveHeapTestClass) + 1;
1217 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1218 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1219 _archived_ArchiveHeapTestClass = array;
1220 }
1221 #endif
1222 if (log_is_enabled(Info, cds, heap)) {
1223 print_stats();
1224 }
1225 }
1226
1227 void HeapShared::add_root_segment(objArrayOop segment_oop) {
1228 assert(segment_oop != nullptr, "must be");
1229 assert(ArchiveHeapLoader::is_in_use(), "must be");
1230 if (_root_segments == nullptr) {
1231 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
1232 }
1233 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
1234 }
1235
1236 void HeapShared::init_root_segment_sizes(int max_size_elems) {
1237 _root_segment_max_size_elems = max_size_elems;
1238 }
1239
1240 void HeapShared::serialize_tables(SerializeClosure* soc) {
1241
1242 #ifndef PRODUCT
1243 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1244 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1245 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1246 setup_test_class(_test_class_name);
1247 }
1248 #endif
1249
1250 _run_time_subgraph_info_table.serialize_header(soc);
1251 soc->do_ptr(&_run_time_special_subgraph);
1252 }
1253
1254 static void verify_the_heap(Klass* k, const char* which) {
1255 if (VerifyArchivedFields > 0) {
1256 ResourceMark rm;
1257 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
1258 which, k->external_name());
1259
1260 VM_Verify verify_op;
1261 VMThread::execute(&verify_op);
1262
1263 if (VerifyArchivedFields > 1 && is_init_completed()) {
1264 // At this time, the oop->klass() of some archived objects in the heap may not
1265 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1266 // have enough information (object size, oop maps, etc) so that a GC can be safely
1267 // performed.
1268 //
1269 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1270 // to check for GC safety.
1271 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
1272 which, k->external_name());
1273 FlagSetting fs1(VerifyBeforeGC, true);
1274 FlagSetting fs2(VerifyDuringGC, true);
1275 FlagSetting fs3(VerifyAfterGC, true);
1276 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1277 }
1278 }
1279 }
1280
1281 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1282 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1283 //
1284 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1285 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1286 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1287 void HeapShared::resolve_classes(JavaThread* current) {
1288 assert(CDSConfig::is_using_archive(), "runtime only!");
1289 if (!ArchiveHeapLoader::is_in_use()) {
1290 return; // nothing to do
1291 }
1292
1293 if (!CDSConfig::is_using_aot_linked_classes()) {
1294 assert( _run_time_special_subgraph != nullptr, "must be");
1295 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1296 if (klasses != nullptr) {
1297 for (int i = 0; i < klasses->length(); i++) {
1298 Klass* k = klasses->at(i);
1299 ExceptionMark em(current); // no exception can happen here
1300 resolve_or_init(k, /*do_init*/false, current);
1301 }
1302 }
1303 }
1304
1305 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1306 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1307 }
1308
1309 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1310 for (int i = 0; fields[i].valid(); i++) {
1311 ArchivableStaticFieldInfo* info = &fields[i];
1312 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1313 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1314 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
1315 resolve_classes_for_subgraph_of(current, k);
1316 }
1317 }
1318
1319 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1320 JavaThread* THREAD = current;
1321 ExceptionMark em(THREAD);
1322 const ArchivedKlassSubGraphInfoRecord* record =
1323 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1324 if (HAS_PENDING_EXCEPTION) {
1325 CLEAR_PENDING_EXCEPTION;
1326 }
1327 if (record == nullptr) {
1328 clear_archived_roots_of(k);
1329 }
1330 }
1331
1332 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1333 if (CDSConfig::is_loading_invokedynamic() || CDSConfig::is_dumping_invokedynamic()) {
1334 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1335 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1336 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1337 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1338 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1339 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1340 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1341 }
1342 }
1343
1344 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1345 // - interned strings
1346 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1347 // - ConstantPool::resolved_references()
1348 // - Universe::<xxx>_exception_instance()
1349 //
1350 // For example, if this enum class is initialized at AOT cache assembly time:
1351 //
1352 // enum Fruit {
1353 // APPLE, ORANGE, BANANA;
1354 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1355 // }
1356 //
1357 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1358 // should be initialized before any Java code can access the Fruit class. Note that
1359 // HashSet itself doesn't necessary need to be an aot-initialized class.
1360 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1361 if (!ArchiveHeapLoader::is_in_use()) {
1362 return;
1363 }
1364
1365 assert( _run_time_special_subgraph != nullptr, "must be");
1366 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1367 if (klasses != nullptr) {
1368 for (int pass = 0; pass < 2; pass ++) {
1369 for (int i = 0; i < klasses->length(); i++) {
1370 Klass* k = klasses->at(i);
1371 if (k->class_loader_data() == nullptr) {
1372 // This class is not yet loaded. We will initialize it in a later phase.
1373 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1374 // but k is part of AOTLinkedClassCategory::BOOT2.
1375 continue;
1376 }
1377 if (k->class_loader() == class_loader()) {
1378 if (pass == 0) {
1379 if (k->is_instance_klass()) {
1380 InstanceKlass::cast(k)->link_class(CHECK);
1381 }
1382 } else {
1383 resolve_or_init(k, /*do_init*/true, CHECK);
1384 }
1385 }
1386 }
1387 }
1388 }
1389 }
1390
1391 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1392 JavaThread* THREAD = current;
1393 if (!ArchiveHeapLoader::is_in_use()) {
1394 return; // nothing to do
1395 }
1396
1397 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1398 !CDSConfig::is_using_optimized_module_handling() &&
1399 // archive was created with --module-path
1400 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1401 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1402 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1403 log_info(cds, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1404 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1405 AOTClassLocationConfig::runtime()->num_module_paths());
1406 return;
1407 }
1408
1409 ExceptionMark em(THREAD);
1410 const ArchivedKlassSubGraphInfoRecord* record =
1411 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1412
1413 if (HAS_PENDING_EXCEPTION) {
1414 CLEAR_PENDING_EXCEPTION;
1415 // None of the field value will be set if there was an exception when initializing the classes.
1416 // The java code will not see any of the archived objects in the
1417 // subgraphs referenced from k in this case.
1418 return;
1419 }
1420
1421 if (record != nullptr) {
1422 init_archived_fields_for(k, record);
1423 }
1424 }
1425
1426 const ArchivedKlassSubGraphInfoRecord*
1427 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1428 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1429
1430 if (!k->is_shared()) {
1431 return nullptr;
1432 }
1433 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1434 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1435
1436 #ifndef PRODUCT
1437 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1438 _test_class = k;
1439 _test_class_record = record;
1440 }
1441 #endif
1442
1443 // Initialize from archived data. Currently this is done only
1444 // during VM initialization time. No lock is needed.
1445 if (record == nullptr) {
1446 if (log_is_enabled(Info, cds, heap)) {
1447 ResourceMark rm(THREAD);
1448 log_info(cds, heap)("subgraph %s is not recorded",
1449 k->external_name());
1450 }
1451 return nullptr;
1452 } else {
1453 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1454 if (log_is_enabled(Info, cds, heap)) {
1455 ResourceMark rm(THREAD);
1456 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
1457 k->external_name());
1458 }
1459 return nullptr;
1460 }
1461
1462 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1463 if (log_is_enabled(Info, cds, heap)) {
1464 ResourceMark rm(THREAD);
1465 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1466 k->external_name());
1467 }
1468 return nullptr;
1469 }
1470
1471 if (log_is_enabled(Info, cds, heap)) {
1472 ResourceMark rm;
1473 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1474 }
1475
1476 resolve_or_init(k, do_init, CHECK_NULL);
1477
1478 // Load/link/initialize the klasses of the objects in the subgraph.
1479 // nullptr class loader is used.
1480 Array<Klass*>* klasses = record->subgraph_object_klasses();
1481 if (klasses != nullptr) {
1482 for (int i = 0; i < klasses->length(); i++) {
1483 Klass* klass = klasses->at(i);
1484 if (!klass->is_shared()) {
1485 return nullptr;
1486 }
1487 resolve_or_init(klass, do_init, CHECK_NULL);
1488 }
1489 }
1490 }
1491
1492 return record;
1493 }
1494
1495 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1496 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1497 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1498 if (k == nullptr) {
1499 return;
1500 }
1501 assert(k->is_shared_boot_class(), "sanity");
1502 resolve_or_init(k, false, CHECK);
1503 if (do_init) {
1504 resolve_or_init(k, true, CHECK);
1505 }
1506 }
1507
1508 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1509 if (!do_init) {
1510 if (k->class_loader_data() == nullptr) {
1511 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1512 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1513 }
1514 } else {
1515 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1516 if (k->is_instance_klass()) {
1517 InstanceKlass* ik = InstanceKlass::cast(k);
1518 ik->initialize(CHECK);
1519 } else if (k->is_objArray_klass()) {
1520 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1521 oak->initialize(CHECK);
1522 }
1523 }
1524 }
1525
1526 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1527 verify_the_heap(k, "before");
1528
1529 // Load the subgraph entry fields from the record and store them back to
1530 // the corresponding fields within the mirror.
1531 oop m = k->java_mirror();
1532 Array<int>* entry_field_records = record->entry_field_records();
1533 if (entry_field_records != nullptr) {
1534 int efr_len = entry_field_records->length();
1535 assert(efr_len % 2 == 0, "sanity");
1536 for (int i = 0; i < efr_len; i += 2) {
1537 int field_offset = entry_field_records->at(i);
1538 int root_index = entry_field_records->at(i+1);
1539 oop v = get_root(root_index, /*clear=*/true);
1540 if (k->has_aot_initialized_mirror()) {
1541 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1542 } else {
1543 m->obj_field_put(field_offset, v);
1544 }
1545 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1546 }
1547
1548 // Done. Java code can see the archived sub-graphs referenced from k's
1549 // mirror after this point.
1550 if (log_is_enabled(Info, cds, heap)) {
1551 ResourceMark rm;
1552 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1553 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1554 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1555 }
1556 }
1557
1558 verify_the_heap(k, "after ");
1559 }
1560
1561 void HeapShared::clear_archived_roots_of(Klass* k) {
1562 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1563 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1564 if (record != nullptr) {
1565 Array<int>* entry_field_records = record->entry_field_records();
1566 if (entry_field_records != nullptr) {
1567 int efr_len = entry_field_records->length();
1568 assert(efr_len % 2 == 0, "sanity");
1569 for (int i = 0; i < efr_len; i += 2) {
1570 int root_index = entry_field_records->at(i+1);
1571 clear_root(root_index);
1572 }
1573 }
1574 }
1575 }
1576
1577 // Push all oops that are referenced by _referencing_obj onto the _stack.
1578 class HeapShared::ReferentPusher: public BasicOopIterateClosure {
1579 PendingOopStack* _stack;
1580 GrowableArray<oop> _found_oop_fields;
1581 int _level;
1582 bool _record_klasses_only;
1583 KlassSubGraphInfo* _subgraph_info;
1584 oop _referencing_obj;
1585 public:
1586 ReferentPusher(PendingOopStack* stack,
1587 int level,
1588 bool record_klasses_only,
1589 KlassSubGraphInfo* subgraph_info,
1590 oop orig) :
1591 _stack(stack),
1592 _found_oop_fields(),
1593 _level(level),
1594 _record_klasses_only(record_klasses_only),
1595 _subgraph_info(subgraph_info),
1596 _referencing_obj(orig) {
1597 }
1598 void do_oop(narrowOop *p) { ReferentPusher::do_oop_work(p); }
1599 void do_oop( oop *p) { ReferentPusher::do_oop_work(p); }
1600
1601 ~ReferentPusher() {
1602 while (_found_oop_fields.length() > 0) {
1603 // This produces the exact same traversal order as the previous version
1604 // of ReferentPusher that recurses on the C stack -- a depth-first search,
1605 // walking the oop fields in _referencing_obj by ascending field offsets.
1606 oop obj = _found_oop_fields.pop();
1607 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1608 }
1609 }
1610
1611 protected:
1612 template <class T> void do_oop_work(T *p) {
1613 oop obj = RawAccess<>::oop_load(p);
1614 if (!CompressedOops::is_null(obj)) {
1615 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1616
1617 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1618 ResourceMark rm;
1619 log_debug(cds, heap)("(%d) %s[%zu] ==> " PTR_FORMAT " size %zu %s", _level,
1620 _referencing_obj->klass()->external_name(), field_delta,
1621 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1622 if (log_is_enabled(Trace, cds, heap)) {
1623 LogTarget(Trace, cds, heap) log;
1624 LogStream out(log);
1625 obj->print_on(&out);
1626 }
1627 }
1628
1629 _found_oop_fields.push(obj);
1630 }
1631 }
1632
1633 public:
1634 oop referencing_obj() { return _referencing_obj; }
1635 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1636 };
1637
1638
1639 // Checks if an oop has any non-null oop fields
1640 class PointsToOopsChecker : public BasicOopIterateClosure {
1641 bool _result;
1642
1643 template <class T> void check(T *p) {
1644 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1645 }
1646
1647 public:
1648 PointsToOopsChecker() : _result(false) {}
1649 void do_oop(narrowOop *p) { check(p); }
1650 void do_oop( oop *p) { check(p); }
1651 bool result() { return _result; }
1652 };
1653
1654 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1655 PointsToOopsChecker points_to_oops_checker;
1656 obj->oop_iterate(&points_to_oops_checker);
1657 return CachedOopInfo(referrer, points_to_oops_checker.result());
1658 }
1659
1660 void HeapShared::init_box_classes(TRAPS) {
1661 if (ArchiveHeapLoader::is_in_use()) {
1662 vmClasses::Boolean_klass()->initialize(CHECK);
1663 vmClasses::Character_klass()->initialize(CHECK);
1664 vmClasses::Float_klass()->initialize(CHECK);
1665 vmClasses::Double_klass()->initialize(CHECK);
1666 vmClasses::Byte_klass()->initialize(CHECK);
1667 vmClasses::Short_klass()->initialize(CHECK);
1668 vmClasses::Integer_klass()->initialize(CHECK);
1669 vmClasses::Long_klass()->initialize(CHECK);
1670 vmClasses::Void_klass()->initialize(CHECK);
1671 }
1672 }
1673
1674 void HeapShared::exit_on_error() {
1675 if (_context != nullptr) {
1676 ResourceMark rm;
1677 LogStream ls(Log(cds, heap)::error());
1678 ls.print_cr("Context");
1679 for (int i = 0; i < _context->length(); i++) {
1680 const char* s = _context->at(i);
1681 ls.print_cr("- %s", s);
1682 }
1683 }
1684 debug_trace();
1685 MetaspaceShared::unrecoverable_writing_error();
1686 }
1687
1688 // (1) If orig_obj has not been archived yet, archive it.
1689 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1690 // trace all objects that are reachable from it, and make sure these objects are archived.
1691 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1692 // were already archived when this function is called)
1693 bool HeapShared::archive_reachable_objects_from(int level,
1694 KlassSubGraphInfo* subgraph_info,
1695 oop orig_obj) {
1696 PendingOopStack stack;
1697 stack.push(PendingOop(orig_obj, nullptr, level));
1698
1699 while (stack.length() > 0) {
1700 PendingOop po = stack.pop();
1701 _object_being_archived = po;
1702 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1703 _object_being_archived = PendingOop();
1704
1705 if (!status) {
1706 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1707 // as the Java code will take care of initializing this field dynamically.
1708 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1709 return false;
1710 }
1711 }
1712
1713 return true;
1714 }
1715
1716 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1717 oop orig_obj, oop referrer) {
1718 assert(orig_obj != nullptr, "must be");
1719 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1720 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1721 // If you get an error here, you probably made a change in the JDK library that has added
1722 // these objects that are referenced (directly or indirectly) by static fields.
1723 ResourceMark rm;
1724 log_error(cds, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1725 exit_on_error();
1726 }
1727
1728 if (log_is_enabled(Debug, cds, heap) && java_lang_Class::is_instance(orig_obj)) {
1729 ResourceMark rm;
1730 LogTarget(Debug, cds, heap) log;
1731 LogStream out(log);
1732 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1733 Klass* k = java_lang_Class::as_Klass(orig_obj);
1734 if (k != nullptr) {
1735 out.print("%s", k->external_name());
1736 } else {
1737 out.print("primitive");
1738 }
1739 out.print_cr("; scratch mirror = " PTR_FORMAT,
1740 p2i(scratch_java_mirror(orig_obj)));
1741 }
1742
1743 if (CDSConfig::is_initing_classes_at_dump_time()) {
1744 if (java_lang_Class::is_instance(orig_obj)) {
1745 orig_obj = scratch_java_mirror(orig_obj);
1746 assert(orig_obj != nullptr, "must be archived");
1747 }
1748 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1749 // Without CDSConfig::is_initing_classes_at_dump_time(), we only allow archived objects to
1750 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1751 // very early by HeapShared::init_box_classes().
1752 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1753 || java_lang_Class::is_primitive(orig_obj)
1754 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1755 || orig_obj == vmClasses::Character_klass()->java_mirror()
1756 || orig_obj == vmClasses::Float_klass()->java_mirror()
1757 || orig_obj == vmClasses::Double_klass()->java_mirror()
1758 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1759 || orig_obj == vmClasses::Short_klass()->java_mirror()
1760 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1761 || orig_obj == vmClasses::Long_klass()->java_mirror()
1762 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1763 orig_obj = scratch_java_mirror(orig_obj);
1764 assert(orig_obj != nullptr, "must be archived");
1765 } else {
1766 // If you get an error here, you probably made a change in the JDK library that has added a Class
1767 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1768 // defined at the top of this file.
1769 log_error(cds, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1770 debug_trace();
1771 MetaspaceShared::unrecoverable_writing_error();
1772 }
1773 }
1774
1775 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1776 // orig_obj has already been archived and traced. Nothing more to do.
1777 return true;
1778 } else {
1779 set_has_been_seen_during_subgraph_recording(orig_obj);
1780 }
1781
1782 bool already_archived = has_been_archived(orig_obj);
1783 bool record_klasses_only = already_archived;
1784 if (!already_archived) {
1785 ++_num_new_archived_objs;
1786 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1787 // Skip archiving the sub-graph referenced from the current entry field.
1788 ResourceMark rm;
1789 log_error(cds, heap)(
1790 "Cannot archive the sub-graph referenced from %s object ("
1791 PTR_FORMAT ") size %zu, skipped.",
1792 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1793 if (level == 1) {
1794 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1795 // as the Java code will take care of initializing this field dynamically.
1796 return false;
1797 } else {
1798 // We don't know how to handle an object that has been archived, but some of its reachable
1799 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1800 // we have a real use case.
1801 exit_on_error();
1802 }
1803 }
1804 }
1805
1806 Klass *orig_k = orig_obj->klass();
1807 subgraph_info->add_subgraph_object_klass(orig_k);
1808
1809 {
1810 // Find all the oops that are referenced by orig_obj, push them onto the stack
1811 // so we can work on them next.
1812 ResourceMark rm;
1813 ReferentPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1814 orig_obj->oop_iterate(&pusher);
1815 }
1816
1817 if (CDSConfig::is_initing_classes_at_dump_time()) {
1818 // The enum klasses are archived with aot-initialized mirror.
1819 // See AOTClassInitializer::can_archive_initialized_mirror().
1820 } else {
1821 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1822 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1823 }
1824 }
1825
1826 return true;
1827 }
1828
1829 //
1830 // Start from the given static field in a java mirror and archive the
1831 // complete sub-graph of java heap objects that are reached directly
1832 // or indirectly from the starting object by following references.
1833 // Sub-graph archiving restrictions (current):
1834 //
1835 // - All classes of objects in the archived sub-graph (including the
1836 // entry class) must be boot class only.
1837 // - No java.lang.Class instance (java mirror) can be included inside
1838 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1839 //
1840 // The Java heap object sub-graph archiving process (see ReferentPusher):
1841 //
1842 // 1) Java object sub-graph archiving starts from a given static field
1843 // within a Class instance (java mirror). If the static field is a
1844 // reference field and points to a non-null java object, proceed to
1845 // the next step.
1846 //
1847 // 2) Archives the referenced java object. If an archived copy of the
1848 // current object already exists, updates the pointer in the archived
1849 // copy of the referencing object to point to the current archived object.
1850 // Otherwise, proceed to the next step.
1851 //
1852 // 3) Follows all references within the current java object and recursively
1853 // archive the sub-graph of objects starting from each reference.
1854 //
1855 // 4) Updates the pointer in the archived copy of referencing object to
1856 // point to the current archived object.
1857 //
1858 // 5) The Klass of the current java object is added to the list of Klasses
1859 // for loading and initializing before any object in the archived graph can
1860 // be accessed at runtime.
1861 //
1862 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1863 const char* klass_name,
1864 int field_offset,
1865 const char* field_name) {
1866 assert(CDSConfig::is_dumping_heap(), "dump time only");
1867 assert(k->is_shared_boot_class(), "must be boot class");
1868
1869 oop m = k->java_mirror();
1870
1871 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1872 oop f = m->obj_field(field_offset);
1873
1874 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1875
1876 if (!CompressedOops::is_null(f)) {
1877 if (log_is_enabled(Trace, cds, heap)) {
1878 LogTarget(Trace, cds, heap) log;
1879 LogStream out(log);
1880 f->print_on(&out);
1881 }
1882
1883 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1884 if (!success) {
1885 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1886 klass_name, field_name);
1887 } else {
1888 // Note: the field value is not preserved in the archived mirror.
1889 // Record the field as a new subGraph entry point. The recorded
1890 // information is restored from the archive at runtime.
1891 subgraph_info->add_subgraph_entry_field(field_offset, f);
1892 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1893 }
1894 } else {
1895 // The field contains null, we still need to record the entry point,
1896 // so it can be restored at runtime.
1897 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1898 }
1899 }
1900
1901 #ifndef PRODUCT
1902 class VerifySharedOopClosure: public BasicOopIterateClosure {
1903 public:
1904 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1905 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1906
1907 protected:
1908 template <class T> void do_oop_work(T *p) {
1909 oop obj = RawAccess<>::oop_load(p);
1910 if (!CompressedOops::is_null(obj)) {
1911 HeapShared::verify_reachable_objects_from(obj);
1912 }
1913 }
1914 };
1915
1916 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1917 assert(CDSConfig::is_dumping_heap(), "dump time only");
1918 assert(k->is_shared_boot_class(), "must be boot class");
1919
1920 oop m = k->java_mirror();
1921 oop f = m->obj_field(field_offset);
1922 if (!CompressedOops::is_null(f)) {
1923 verify_subgraph_from(f);
1924 }
1925 }
1926
1927 void HeapShared::verify_subgraph_from(oop orig_obj) {
1928 if (!has_been_archived(orig_obj)) {
1929 // It's OK for the root of a subgraph to be not archived. See comments in
1930 // archive_reachable_objects_from().
1931 return;
1932 }
1933
1934 // Verify that all objects reachable from orig_obj are archived.
1935 init_seen_objects_table();
1936 verify_reachable_objects_from(orig_obj);
1937 delete_seen_objects_table();
1938 }
1939
1940 void HeapShared::verify_reachable_objects_from(oop obj) {
1941 _num_total_verifications ++;
1942 if (java_lang_Class::is_instance(obj)) {
1943 obj = scratch_java_mirror(obj);
1944 assert(obj != nullptr, "must be");
1945 }
1946 if (!has_been_seen_during_subgraph_recording(obj)) {
1947 set_has_been_seen_during_subgraph_recording(obj);
1948 assert(has_been_archived(obj), "must be");
1949 VerifySharedOopClosure walker;
1950 obj->oop_iterate(&walker);
1951 }
1952 }
1953 #endif
1954
1955 void HeapShared::check_special_subgraph_classes() {
1956 if (CDSConfig::is_initing_classes_at_dump_time()) {
1957 // We can have aot-initialized classes (such as Enums) that can reference objects
1958 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
1959 // aot-initialize classes that are "safe".
1960 //
1961 // TODO: we need an automatic tool that checks the safety of aot-initialized
1962 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
1963 return;
1964 } else {
1965 // In this case, the special subgraph should contain a few specific types
1966 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
1967 int num = klasses->length();
1968 for (int i = 0; i < num; i++) {
1969 Klass* subgraph_k = klasses->at(i);
1970 Symbol* name = subgraph_k->name();
1971 if (subgraph_k->is_instance_klass() &&
1972 name != vmSymbols::java_lang_Class() &&
1973 name != vmSymbols::java_lang_String() &&
1974 name != vmSymbols::java_lang_ArithmeticException() &&
1975 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
1976 name != vmSymbols::java_lang_ArrayStoreException() &&
1977 name != vmSymbols::java_lang_ClassCastException() &&
1978 name != vmSymbols::java_lang_InternalError() &&
1979 name != vmSymbols::java_lang_NullPointerException()) {
1980 ResourceMark rm;
1981 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
1982 }
1983 }
1984 }
1985 }
1986
1987 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1988 HeapShared::PendingOop HeapShared::_object_being_archived;
1989 int HeapShared::_num_new_walked_objs;
1990 int HeapShared::_num_new_archived_objs;
1991 int HeapShared::_num_old_recorded_klasses;
1992
1993 int HeapShared::_num_total_subgraph_recordings = 0;
1994 int HeapShared::_num_total_walked_objs = 0;
1995 int HeapShared::_num_total_archived_objs = 0;
1996 int HeapShared::_num_total_recorded_klasses = 0;
1997 int HeapShared::_num_total_verifications = 0;
1998
1999 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2000 return _seen_objects_table->get(obj) != nullptr;
2001 }
2002
2003 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2004 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2005 _seen_objects_table->put_when_absent(obj, true);
2006 _seen_objects_table->maybe_grow();
2007 ++ _num_new_walked_objs;
2008 }
2009
2010 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2011 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2012 init_subgraph_info(k, is_full_module_graph);
2013 init_seen_objects_table();
2014 _num_new_walked_objs = 0;
2015 _num_new_archived_objs = 0;
2016 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2017 }
2018
2019 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2020 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2021 _num_old_recorded_klasses;
2022 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
2023 "walked %d objs, archived %d new objs, recorded %d classes",
2024 class_name, _num_new_walked_objs, _num_new_archived_objs,
2025 num_new_recorded_klasses);
2026
2027 delete_seen_objects_table();
2028
2029 _num_total_subgraph_recordings ++;
2030 _num_total_walked_objs += _num_new_walked_objs;
2031 _num_total_archived_objs += _num_new_archived_objs;
2032 _num_total_recorded_klasses += num_new_recorded_klasses;
2033 }
2034
2035 class ArchivableStaticFieldFinder: public FieldClosure {
2036 InstanceKlass* _ik;
2037 Symbol* _field_name;
2038 bool _found;
2039 int _offset;
2040 public:
2041 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2042 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2043
2044 virtual void do_field(fieldDescriptor* fd) {
2045 if (fd->name() == _field_name) {
2046 assert(!_found, "fields can never be overloaded");
2047 if (is_reference_type(fd->field_type())) {
2048 _found = true;
2049 _offset = fd->offset();
2050 }
2051 }
2052 }
2053 bool found() { return _found; }
2054 int offset() { return _offset; }
2055 };
2056
2057 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2058 TRAPS) {
2059 for (int i = 0; fields[i].valid(); i++) {
2060 ArchivableStaticFieldInfo* info = &fields[i];
2061 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2062 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2063 ResourceMark rm; // for stringStream::as_string() etc.
2064
2065 #ifndef PRODUCT
2066 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2067 const char* test_class_name = ArchiveHeapTestClass;
2068 #else
2069 bool is_test_class = false;
2070 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2071 #endif
2072
2073 if (is_test_class) {
2074 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2075 }
2076
2077 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2078 if (HAS_PENDING_EXCEPTION) {
2079 CLEAR_PENDING_EXCEPTION;
2080 stringStream st;
2081 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2082 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2083 }
2084
2085 if (!k->is_instance_klass()) {
2086 stringStream st;
2087 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2088 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2089 }
2090
2091 InstanceKlass* ik = InstanceKlass::cast(k);
2092 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
2093 "Only support boot classes");
2094
2095 if (is_test_class) {
2096 if (ik->module()->is_named()) {
2097 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2098 // core-lib classes. You need to at least append to the bootclasspath.
2099 stringStream st;
2100 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2101 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2102 }
2103
2104 if (ik->package() != nullptr) {
2105 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2106 stringStream st;
2107 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2108 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2109 }
2110 } else {
2111 if (ik->module()->name() != vmSymbols::java_base()) {
2112 // We don't want to deal with cases when a module is unavailable at runtime.
2113 // FUTURE -- load from archived heap only when module graph has not changed
2114 // between dump and runtime.
2115 stringStream st;
2116 st.print("%s is not in java.base module", info->klass_name);
2117 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2118 }
2119 }
2120
2121 if (is_test_class) {
2122 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2123 }
2124 ik->initialize(CHECK);
2125
2126 ArchivableStaticFieldFinder finder(ik, field_name);
2127 ik->do_local_static_fields(&finder);
2128 if (!finder.found()) {
2129 stringStream st;
2130 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2131 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2132 }
2133
2134 info->klass = ik;
2135 info->offset = finder.offset();
2136 }
2137 }
2138
2139 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2140 assert(CDSConfig::is_dumping_heap(), "must be");
2141 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2142 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2143 if (CDSConfig::is_dumping_full_module_graph()) {
2144 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2145 }
2146 }
2147
2148 #ifndef PRODUCT
2149 void HeapShared::setup_test_class(const char* test_class_name) {
2150 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2151 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2152 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2153 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2154
2155 if (test_class_name != nullptr) {
2156 p[num_slots - 2].klass_name = test_class_name;
2157 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2158 }
2159 }
2160
2161 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2162 // during runtime. This may be called before the module system is initialized so
2163 // we cannot rely on InstanceKlass::module(), etc.
2164 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2165 if (_test_class != nullptr) {
2166 if (ik == _test_class) {
2167 return true;
2168 }
2169 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2170 if (klasses == nullptr) {
2171 return false;
2172 }
2173
2174 for (int i = 0; i < klasses->length(); i++) {
2175 Klass* k = klasses->at(i);
2176 if (k == ik) {
2177 Symbol* name;
2178 if (k->is_instance_klass()) {
2179 name = InstanceKlass::cast(k)->name();
2180 } else if (k->is_objArray_klass()) {
2181 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2182 if (!bk->is_instance_klass()) {
2183 return false;
2184 }
2185 name = bk->name();
2186 } else {
2187 return false;
2188 }
2189
2190 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2191 // to be:
2192 // (A) java.base classes (which must not be in the unnamed module)
2193 // (B) test classes which must be in the unnamed package of the unnamed module.
2194 // So if we see a '/' character in the class name, it must be in (A);
2195 // otherwise it must be in (B).
2196 if (name->index_of_at(0, "/", 1) >= 0) {
2197 return false; // (A)
2198 }
2199
2200 return true; // (B)
2201 }
2202 }
2203 }
2204
2205 return false;
2206 }
2207
2208 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2209 Klass* k = _test_class;
2210 if (k != nullptr && ArchiveHeapLoader::is_in_use()) {
2211 JavaThread* THREAD = current;
2212 ExceptionMark em(THREAD);
2213 const ArchivedKlassSubGraphInfoRecord* record =
2214 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2215
2216 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2217 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2218 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2219 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2220 if (record != nullptr) {
2221 init_archived_fields_for(k, record);
2222 }
2223 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2224 }
2225 }
2226 #endif
2227
2228 void HeapShared::init_for_dumping(TRAPS) {
2229 if (CDSConfig::is_dumping_heap()) {
2230 setup_test_class(ArchiveHeapTestClass);
2231 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
2232 init_subgraph_entry_fields(CHECK);
2233 }
2234 }
2235
2236 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2237 bool is_full_module_graph) {
2238 _num_total_subgraph_recordings = 0;
2239 _num_total_walked_objs = 0;
2240 _num_total_archived_objs = 0;
2241 _num_total_recorded_klasses = 0;
2242 _num_total_verifications = 0;
2243
2244 // For each class X that has one or more archived fields:
2245 // [1] Dump the subgraph of each archived field
2246 // [2] Create a list of all the class of the objects that can be reached
2247 // by any of these static fields.
2248 // At runtime, these classes are initialized before X's archived fields
2249 // are restored by HeapShared::initialize_from_archived_subgraph().
2250 for (int i = 0; fields[i].valid(); ) {
2251 ArchivableStaticFieldInfo* info = &fields[i];
2252 const char* klass_name = info->klass_name;
2253 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2254
2255 ContextMark cm(klass_name);
2256 // If you have specified consecutive fields of the same klass in
2257 // fields[], these will be archived in the same
2258 // {start_recording_subgraph ... done_recording_subgraph} pass to
2259 // save time.
2260 for (; fields[i].valid(); i++) {
2261 ArchivableStaticFieldInfo* f = &fields[i];
2262 if (f->klass_name != klass_name) {
2263 break;
2264 }
2265
2266 ContextMark cm(f->field_name);
2267 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2268 f->offset, f->field_name);
2269 }
2270 done_recording_subgraph(info->klass, klass_name);
2271 }
2272
2273 log_info(cds, heap)("Archived subgraph records = %d",
2274 _num_total_subgraph_recordings);
2275 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
2276 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
2277 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
2278
2279 #ifndef PRODUCT
2280 for (int i = 0; fields[i].valid(); i++) {
2281 ArchivableStaticFieldInfo* f = &fields[i];
2282 verify_subgraph_from_static_field(f->klass, f->offset);
2283 }
2284 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
2285 #endif
2286 }
2287
2288 // Not all the strings in the global StringTable are dumped into the archive, because
2289 // some of those strings may be only referenced by classes that are excluded from
2290 // the archive. We need to explicitly mark the strings that are:
2291 // [1] used by classes that WILL be archived;
2292 // [2] included in the SharedArchiveConfigFile.
2293 void HeapShared::add_to_dumped_interned_strings(oop string) {
2294 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
2295 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
2296 bool created;
2297 _dumped_interned_strings->put_if_absent(string, true, &created);
2298 if (created) {
2299 // Prevent string deduplication from changing the value field to
2300 // something not in the archive.
2301 java_lang_String::set_deduplication_forbidden(string);
2302 _dumped_interned_strings->maybe_grow();
2303 }
2304 }
2305
2306 bool HeapShared::is_dumped_interned_string(oop o) {
2307 return _dumped_interned_strings->get(o) != nullptr;
2308 }
2309
2310 void HeapShared::debug_trace() {
2311 ResourceMark rm;
2312 oop referrer = _object_being_archived.referrer();
2313 if (referrer != nullptr) {
2314 LogStream ls(Log(cds, heap)::error());
2315 ls.print_cr("Reference trace");
2316 CDSHeapVerifier::trace_to_root(&ls, referrer);
2317 }
2318 }
2319
2320 #ifndef PRODUCT
2321 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2322 // region. This way we can quickly relocate all the pointers without using
2323 // BasicOopIterateClosure at runtime.
2324 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2325 void* _start;
2326 BitMap *_oopmap;
2327 int _num_total_oops;
2328 int _num_null_oops;
2329 public:
2330 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2331 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2332
2333 virtual void do_oop(narrowOop* p) {
2334 assert(UseCompressedOops, "sanity");
2335 _num_total_oops ++;
2336 narrowOop v = *p;
2337 if (!CompressedOops::is_null(v)) {
2338 size_t idx = p - (narrowOop*)_start;
2339 _oopmap->set_bit(idx);
2340 } else {
2341 _num_null_oops ++;
2342 }
2343 }
2344 virtual void do_oop(oop* p) {
2345 assert(!UseCompressedOops, "sanity");
2346 _num_total_oops ++;
2347 if ((*p) != nullptr) {
2348 size_t idx = p - (oop*)_start;
2349 _oopmap->set_bit(idx);
2350 } else {
2351 _num_null_oops ++;
2352 }
2353 }
2354 int num_total_oops() const { return _num_total_oops; }
2355 int num_null_oops() const { return _num_null_oops; }
2356 };
2357 #endif
2358
2359 void HeapShared::count_allocation(size_t size) {
2360 _total_obj_count ++;
2361 _total_obj_size += size;
2362 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2363 if (size <= (size_t(1) << i)) {
2364 _alloc_count[i] ++;
2365 _alloc_size[i] += size;
2366 return;
2367 }
2368 }
2369 }
2370
2371 static double avg_size(size_t size, size_t count) {
2372 double avg = 0;
2373 if (count > 0) {
2374 avg = double(size * HeapWordSize) / double(count);
2375 }
2376 return avg;
2377 }
2378
2379 void HeapShared::print_stats() {
2380 size_t huge_count = _total_obj_count;
2381 size_t huge_size = _total_obj_size;
2382
2383 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2384 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2385 size_t count = _alloc_count[i];
2386 size_t size = _alloc_size[i];
2387 log_info(cds, heap)("%8zu objects are <= %-6zu"
2388 " bytes (total %8zu bytes, avg %8.1f bytes)",
2389 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2390 huge_count -= count;
2391 huge_size -= size;
2392 }
2393
2394 log_info(cds, heap)("%8zu huge objects (total %8zu bytes"
2395 ", avg %8.1f bytes)",
2396 huge_count, huge_size * HeapWordSize,
2397 avg_size(huge_size, huge_count));
2398 log_info(cds, heap)("%8zu total objects (total %8zu bytes"
2399 ", avg %8.1f bytes)",
2400 _total_obj_count, _total_obj_size * HeapWordSize,
2401 avg_size(_total_obj_size, _total_obj_count));
2402 }
2403
2404 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2405 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2406 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2407 if (k == nullptr) {
2408 return false;
2409 } else {
2410 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2411 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2412 fieldDescriptor fd;
2413 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2414 oop m = k->java_mirror();
2415 oop f = m->obj_field(fd.offset());
2416 if (CompressedOops::is_null(f)) {
2417 return false;
2418 }
2419 } else {
2420 return false;
2421 }
2422 }
2423 return true;
2424 }
2425
2426 #endif // INCLUDE_CDS_JAVA_HEAP